hdu4279 Number-------天津网络赛 打表找规律

NumberTime Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 492    Accepted Submission(s): 159


Problem DescriptionInputOutputSample InputSample OutputSourceRecommend#include<iostream>#include<cstdlib>#include<stdio.h>#include<math.h>using namespace std;#define ll __int64ll a[110];int main(){ a[1]=0; for(int i=2;i<=50;i++) { int count=0; for(int j=2;j<i;j++) { if(i%j==0) continue; bool flag=false; for(int k=2;k<j;k++) { if(j%k==0&&i%k==0) { flag=true;break; } } if(flag&&(i%j!=0)) { // cout<<i<<" "<<j<<"*"<<endl; count++; } } if(count&1) a[i]=a[i-1]+1; else a[i]=a[i-1]; cout<<i<<" "<<a[i]<<endl; }}
规律：long long xx = (long long)sqrt(x * 1.0);    if(xx & 1)    {        return ((x - 4) >> 1) + 1;    }    else    {        return ((x - 4) >> 1);    }